XML inside another XML

I have an XML used as a wrapper, that contains another XML. ( The outside XML is used as the communication header )
I have to handle a case where the inside XML is not well formed. ( Basically I m sending a response message saying that the request XML was corrupt )
Obviously if I just embedd the corrupt XML inside the wrapper XML, I get error.
What are the possibilities here ?
1. using Cdata ?
2. Is there any way/method is java wherin I can convert the inside XML to a '<', '>' kind of form ?
3. What is that conversion ( '<', '>' ) called ( encoding ? )

Thanks a lot
--sony